Can We Make Quantum Technology Work: Leo Kouwenhoven (Transcript)

Since these two parts of the same single-electron doesn’t want to be too separated, it actually keeps the oxygen atoms together, so it’s actually a superposition that binds atoms in molecules. Since actually our body consists of molecules, so without superposition, our body would fall apart; and without superposition, all our molecules would fall apart in loose atoms.

So superposition is a good thing. You should like it on Facebook.

Since Einstein, and Bohr, and also other genius scientists developed the principles of quantum mechanics, we’ve been using mostly formulas — formulas to describe nature, as it is given to us.

But now 100 years later, it’s actually time for something new. We now view nature as an information processor, and instead of formulas, we use this symbol to describe that there is an information flow in nature.

And we no longer study nature as it is given to us. We actually have started to design and construct actual subprogram — the machines that we make ourselves; and study how our own designed machines can actually solve quantum problems.

So my job has become to make qubits. Instead of a farmer, instead of a vet, I have become a qubit maker, or a superposition maker. And I want to illustrate that with electrons in boxes.

What you see here in the upper row are two boxes and one electron. In our world, that electron has to choose it can sit on the left or in the right box. In an information description of the same thing, what we say is that in the upper case, when the electron is in the left box, I call it a bit zero; or if it’s in the right box, I call it a bit one. This is actually how we encode information in our normal computers – that’s a bit zero and a bit one.

The special thing that we do in our lab in Delft, is that we can do also superposition. So we can take a single electron and put it in both boxes at the same time, kind of similar the oxygen at a molecule. But now we’ve boxes that we have made ourselves, and if we can also control and program.

When the electron is in both boxes at the same time, in an information description, we say the system is in a qubit state, and the qubit is in a superposition of a bit zero and a bit one at the same time. So it encodes for that information at the same time.

If we have these qubits, we made actually a little animation to illustrate how it can be used to speed up calculations. You see here a labyrinth, and if we put a classical electron into this labyrinth, then the way electrons actually solve classically this problem to find the exit of the labyrinth is what we would do. We try path by path. Every time, we find it’s not the solution, we try again.

Sequentially, we go through the system until we found the exit, but when we find the exit we know we have the right solution. The quantum electron would split itself up, in parallel, in a superposition, take all the paths at the same time; and also reaching the exit, but now a lot faster. And that is the magic of a quantum computer.

All these actions, all these different possibilities, can be checked in a message parallel calculation, and find the answer in a single step, that speeds up the calculation.

What would we do if we have a quantum computer?

What kind of — do we actually have good problems to feed, such a super powerful computer? To answer this question, let’s zoom out a little bit. And ask ourselves, what are actually the big challenges that we face on Earth? The big problems, there’re many big problems. But let’s focus on our natural resources.

Here we are: spoiling energy; we’re wasting materials. Our climate is changing too fast, and many people on Earth don’t get the right medicine. These are very big problems that somehow we have to solve. We have to solve it rather soon at least within the next few decades.

To solve those problems, we need radically new tools. And no one doubts that help from a supercomputer will be of vital importance to actually solve these problems. That’s where the use of the quantum computer can come in.

And universities — I’m working at a university — have started to develop the fundamentals of quantum computers since two decades or so. And in the last few years, also, some of the bigger global IT companies have joined this effort.

When companies join and invest money, they actually have some specific ideas for the purpose, they want to use the quantum computer for, and have made a little list of what they say will be the applications of a quantum computer.

But this list is of course, by far not complete. These are just a few examples. It is impossible to predict what you can do with a new technology.

So we started a new institute in Delft, actually, work in a focused way on developing this quantum computer, it’s called Q-Tech.

In this Institute, we make the hardware. By using nanotechnology, and cleanroom fabrication, we make electronic chips with a whole bunch of qubits, that we can program. By programming these chips, we can learn how quantum systems solve problems.